fix(thinking): fallback to upstream model for thinking support when alias not in registry

internal/runtime/executor/antigravity_executor.go

@@ -96,7 +96,7 @@ func (e *AntigravityExecutor) Execute(ctx context.Context, auth *cliproxyauth.Au
 	to := sdktranslator.FromString("antigravity")
 	translated := sdktranslator.TranslateRequest(from, to, req.Model, bytes.Clone(req.Payload), false)
 
-	translated = applyThinkingMetadataCLI(translated, req.Metadata, req.Model)
+	translated = ApplyThinkingMetadataCLI(translated, req.Metadata, req.Model)
 	translated = util.ApplyGemini3ThinkingLevelFromMetadataCLI(req.Model, req.Metadata, translated)
 	translated = util.ApplyDefaultThinkingIfNeededCLI(req.Model, req.Metadata, translated)
 	translated = normalizeAntigravityThinking(req.Model, translated, isClaude)
@@ -191,7 +191,7 @@ func (e *AntigravityExecutor) executeClaudeNonStream(ctx context.Context, auth *
 	to := sdktranslator.FromString("antigravity")
 	translated := sdktranslator.TranslateRequest(from, to, req.Model, bytes.Clone(req.Payload), true)
 
-	translated = applyThinkingMetadataCLI(translated, req.Metadata, req.Model)
+	translated = ApplyThinkingMetadataCLI(translated, req.Metadata, req.Model)
 	translated = util.ApplyGemini3ThinkingLevelFromMetadataCLI(req.Model, req.Metadata, translated)
 	translated = util.ApplyDefaultThinkingIfNeededCLI(req.Model, req.Metadata, translated)
 	translated = normalizeAntigravityThinking(req.Model, translated, true)
@@ -527,7 +527,7 @@ func (e *AntigravityExecutor) ExecuteStream(ctx context.Context, auth *cliproxya
 	to := sdktranslator.FromString("antigravity")
 	translated := sdktranslator.TranslateRequest(from, to, req.Model, bytes.Clone(req.Payload), true)
 
-	translated = applyThinkingMetadataCLI(translated, req.Metadata, req.Model)
+	translated = ApplyThinkingMetadataCLI(translated, req.Metadata, req.Model)
 	translated = util.ApplyGemini3ThinkingLevelFromMetadataCLI(req.Model, req.Metadata, translated)
 	translated = util.ApplyDefaultThinkingIfNeededCLI(req.Model, req.Metadata, translated)
 	translated = normalizeAntigravityThinking(req.Model, translated, isClaude)
@@ -697,7 +697,7 @@ func (e *AntigravityExecutor) CountTokens(ctx context.Context, auth *cliproxyaut
 
 	for idx, baseURL := range baseURLs {
 		payload := sdktranslator.TranslateRequest(from, to, req.Model, bytes.Clone(req.Payload), false)
-		payload = applyThinkingMetadataCLI(payload, req.Metadata, req.Model)
+		payload = ApplyThinkingMetadataCLI(payload, req.Metadata, req.Model)
 		payload = util.ApplyDefaultThinkingIfNeededCLI(req.Model, req.Metadata, payload)
 		payload = normalizeAntigravityThinking(req.Model, payload, isClaude)
 		payload = deleteJSONField(payload, "project")

internal/runtime/executor/gemini_cli_executor.go

@@ -78,7 +78,7 @@ func (e *GeminiCLIExecutor) Execute(ctx context.Context, auth *cliproxyauth.Auth
 	from := opts.SourceFormat
 	to := sdktranslator.FromString("gemini-cli")
 	basePayload := sdktranslator.TranslateRequest(from, to, req.Model, bytes.Clone(req.Payload), false)
-	basePayload = applyThinkingMetadataCLI(basePayload, req.Metadata, req.Model)
+	basePayload = ApplyThinkingMetadataCLI(basePayload, req.Metadata, req.Model)
 	basePayload = util.ApplyGemini3ThinkingLevelFromMetadataCLI(req.Model, req.Metadata, basePayload)
 	basePayload = util.ApplyDefaultThinkingIfNeededCLI(req.Model, req.Metadata, basePayload)
 	basePayload = util.NormalizeGeminiCLIThinkingBudget(req.Model, basePayload)
@@ -217,7 +217,7 @@ func (e *GeminiCLIExecutor) ExecuteStream(ctx context.Context, auth *cliproxyaut
 	from := opts.SourceFormat
 	to := sdktranslator.FromString("gemini-cli")
 	basePayload := sdktranslator.TranslateRequest(from, to, req.Model, bytes.Clone(req.Payload), true)
-	basePayload = applyThinkingMetadataCLI(basePayload, req.Metadata, req.Model)
+	basePayload = ApplyThinkingMetadataCLI(basePayload, req.Metadata, req.Model)
 	basePayload = util.ApplyGemini3ThinkingLevelFromMetadataCLI(req.Model, req.Metadata, basePayload)
 	basePayload = util.ApplyDefaultThinkingIfNeededCLI(req.Model, req.Metadata, basePayload)
 	basePayload = util.NormalizeGeminiCLIThinkingBudget(req.Model, basePayload)
@@ -421,7 +421,7 @@ func (e *GeminiCLIExecutor) CountTokens(ctx context.Context, auth *cliproxyauth.
 	// Gemini CLI endpoint when iterating fallback variants.
 	for _, attemptModel := range models {
 		payload := sdktranslator.TranslateRequest(from, to, attemptModel, bytes.Clone(req.Payload), false)
-		payload = applyThinkingMetadataCLI(payload, req.Metadata, req.Model)
+		payload = ApplyThinkingMetadataCLI(payload, req.Metadata, req.Model)
 		payload = util.ApplyGemini3ThinkingLevelFromMetadataCLI(req.Model, req.Metadata, payload)
 		payload = deleteJSONField(payload, "project")
 		payload = deleteJSONField(payload, "model")

internal/runtime/executor/payload_helpers.go

@@ -17,35 +17,51 @@ func ApplyThinkingMetadata(payload []byte, metadata map[string]any, model string
 	// Use the alias from metadata if available, as it's registered in the global registry
 	// with thinking metadata; the upstream model name may not be registered.
 	lookupModel := util.ResolveOriginalModel(model, metadata)
-	budgetOverride, includeOverride, ok := util.ResolveThinkingConfigFromMetadata(lookupModel, metadata)
+
+	// Determine which model to use for thinking support check.
+	// If the alias (lookupModel) is not in the registry, fall back to the upstream model.
+	thinkingModel := lookupModel
+	if !util.ModelSupportsThinking(lookupModel) && util.ModelSupportsThinking(model) {
+		thinkingModel = model
+	}
+
+	budgetOverride, includeOverride, ok := util.ResolveThinkingConfigFromMetadata(thinkingModel, metadata)
 	if !ok || (budgetOverride == nil && includeOverride == nil) {
 		return payload
 	}
-	if !util.ModelSupportsThinking(lookupModel) {
+	if !util.ModelSupportsThinking(thinkingModel) {
 		return payload
 	}
 	if budgetOverride != nil {
-		norm := util.NormalizeThinkingBudget(lookupModel, *budgetOverride)
+		norm := util.NormalizeThinkingBudget(thinkingModel, *budgetOverride)
 		budgetOverride = &norm
 	}
 	return util.ApplyGeminiThinkingConfig(payload, budgetOverride, includeOverride)
 }
 
-// applyThinkingMetadataCLI applies thinking config from model suffix metadata (e.g., (high), (8192))
+// ApplyThinkingMetadataCLI applies thinking config from model suffix metadata (e.g., (high), (8192))
 // for Gemini CLI format payloads (nested under "request"). It normalizes the budget when the model supports thinking.
-func applyThinkingMetadataCLI(payload []byte, metadata map[string]any, model string) []byte {
+func ApplyThinkingMetadataCLI(payload []byte, metadata map[string]any, model string) []byte {
 	// Use the alias from metadata if available, as it's registered in the global registry
 	// with thinking metadata; the upstream model name may not be registered.
 	lookupModel := util.ResolveOriginalModel(model, metadata)
-	budgetOverride, includeOverride, ok := util.ResolveThinkingConfigFromMetadata(lookupModel, metadata)
+
+	// Determine which model to use for thinking support check.
+	// If the alias (lookupModel) is not in the registry, fall back to the upstream model.
+	thinkingModel := lookupModel
+	if !util.ModelSupportsThinking(lookupModel) && util.ModelSupportsThinking(model) {
+		thinkingModel = model
+	}
+
+	budgetOverride, includeOverride, ok := util.ResolveThinkingConfigFromMetadata(thinkingModel, metadata)
 	if !ok || (budgetOverride == nil && includeOverride == nil) {
 		return payload
 	}
-	if !util.ModelSupportsThinking(lookupModel) {
+	if !util.ModelSupportsThinking(thinkingModel) {
 		return payload
 	}
 	if budgetOverride != nil {
-		norm := util.NormalizeThinkingBudget(lookupModel, *budgetOverride)
+		norm := util.NormalizeThinkingBudget(thinkingModel, *budgetOverride)
 		budgetOverride = &norm
 	}
 	return util.ApplyGeminiCLIThinkingConfig(payload, budgetOverride, includeOverride)

internal/util/thinking.go

@@ -12,9 +12,18 @@ func ModelSupportsThinking(model string) bool {
 	if model == "" {
 		return false
 	}
+	// First check the global dynamic registry
 	if info := registry.GetGlobalRegistry().GetModelInfo(model); info != nil {
 		return info.Thinking != nil
 	}
+	// Fallback: check static model definitions
+	if info := registry.LookupStaticModelInfo(model); info != nil {
+		return info.Thinking != nil
+	}
+	// Fallback: check Antigravity static config
+	if cfg := registry.GetAntigravityModelConfig()[model]; cfg != nil {
+		return cfg.Thinking != nil
+	}
 	return false
 }
 
@@ -63,11 +72,19 @@ func thinkingRangeFromRegistry(model string) (found bool, min int, max int, zero
 	if model == "" {
 		return false, 0, 0, false, false
 	}
-	info := registry.GetGlobalRegistry().GetModelInfo(model)
+	// First check global dynamic registry
-	if info == nil || info.Thinking == nil {
+	if info := registry.GetGlobalRegistry().GetModelInfo(model); info != nil && info.Thinking != nil {
-		return false, 0, 0, false, false
-	}
 		return true, info.Thinking.Min, info.Thinking.Max, info.Thinking.ZeroAllowed, info.Thinking.DynamicAllowed
+	}
+	// Fallback: check static model definitions
+	if info := registry.LookupStaticModelInfo(model); info != nil && info.Thinking != nil {
+		return true, info.Thinking.Min, info.Thinking.Max, info.Thinking.ZeroAllowed, info.Thinking.DynamicAllowed
+	}
+	// Fallback: check Antigravity static config
+	if cfg := registry.GetAntigravityModelConfig()[model]; cfg != nil && cfg.Thinking != nil {
+		return true, cfg.Thinking.Min, cfg.Thinking.Max, cfg.Thinking.ZeroAllowed, cfg.Thinking.DynamicAllowed
+	}
+	return false, 0, 0, false, false
 }
 
 // GetModelThinkingLevels returns the discrete reasoning effort levels for the model.

test/model_alias_thinking_suffix_test.go

@@ -3,6 +3,7 @@ package test
 import (
 	"testing"
 
+	"github.com/router-for-me/CLIProxyAPI/v6/internal/runtime/executor"
 	"github.com/router-for-me/CLIProxyAPI/v6/internal/util"
 	"github.com/tidwall/gjson"
 )
@@ -80,8 +81,9 @@ func TestModelAliasThinkingSuffix(t *testing.T) {
 
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			// Step 1: Parse model suffix
+			// Step 1: Parse model suffix (simulates SDK layer normalization)
-			baseModel, metadata := util.NormalizeThinkingModel(tt.requestModel)
+			// For "gp(1000)" -> requestedModel="gp", metadata={thinking_budget: 1000}
+			requestedModel, metadata := util.NormalizeThinkingModel(tt.requestModel)
 
 			// Verify suffix was parsed
 			if metadata == nil && (tt.suffixType == "numeric" || tt.suffixType == "level") {
@@ -89,12 +91,13 @@ func TestModelAliasThinkingSuffix(t *testing.T) {
 				return
 			}
 
-			// Step 2: For aliases, simulate the model mapping by adding upstream model info
+			// Step 2: Simulate OAuth model mapping
+			// Real flow: applyOAuthModelMapping stores requestedModel (the alias) in metadata
 			if tt.isAlias {
 				if metadata == nil {
 					metadata = make(map[string]any)
 				}
-				metadata[util.ModelMappingOriginalModelMetadataKey] = baseModel
+				metadata[util.ModelMappingOriginalModelMetadataKey] = requestedModel
 			}
 
 			// Step 3: Verify metadata extraction
@@ -151,12 +154,15 @@ func TestModelAliasThinkingSuffix(t *testing.T) {
 			if tt.expectedField == "thinkingLevel" && util.IsGemini3Model(tt.upstreamModel) {
 				body := []byte(`{"request":{"contents":[]}}`)
 
-				// Build metadata for the function
+				// Build metadata simulating real OAuth flow:
+				// - requestedModel (alias like "gf") is stored in model_mapping_original_model
+				// - upstreamModel is passed as the model parameter
 				testMetadata := make(map[string]any)
 				if tt.isAlias {
-					testMetadata[util.ModelMappingOriginalModelMetadataKey] = tt.upstreamModel
+					// Real flow: applyOAuthModelMapping stores requestedModel (the alias)
+					testMetadata[util.ModelMappingOriginalModelMetadataKey] = requestedModel
 				}
-				// Copy parsed metadata
+				// Copy parsed metadata (thinking_budget, reasoning_effort, etc.)
 				for k, v := range metadata {
 					testMetadata[k] = v
 				}
@@ -172,12 +178,25 @@ func TestModelAliasThinkingSuffix(t *testing.T) {
 				}
 			}
 
-			// Step 5: Test Gemini 2.5 thinkingBudget application
+			// Step 5: Test Gemini 2.5 thinkingBudget application using real ApplyThinkingMetadataCLI flow
 			if tt.expectedField == "thinkingBudget" && util.IsGemini25Model(tt.upstreamModel) {
-				budget, _, _, _ := util.ThinkingFromMetadata(metadata)
-				if budget != nil {
 				body := []byte(`{"request":{"contents":[]}}`)
-					result := util.ApplyGeminiCLIThinkingConfig(body, budget, nil)
+
+				// Build metadata simulating real OAuth flow:
+				// - requestedModel (alias like "gp") is stored in model_mapping_original_model
+				// - upstreamModel is passed as the model parameter
+				testMetadata := make(map[string]any)
+				if tt.isAlias {
+					// Real flow: applyOAuthModelMapping stores requestedModel (the alias)
+					testMetadata[util.ModelMappingOriginalModelMetadataKey] = requestedModel
+				}
+				// Copy parsed metadata (thinking_budget, reasoning_effort, etc.)
+				for k, v := range metadata {
+					testMetadata[k] = v
+				}
+
+				// Use the exported ApplyThinkingMetadataCLI which includes the fallback logic
+				result := executor.ApplyThinkingMetadataCLI(body, testMetadata, tt.upstreamModel)
 				budgetVal := gjson.GetBytes(result, "request.generationConfig.thinkingConfig.thinkingBudget")
 
 				expectedBudget := tt.expectedValue.(int)
@@ -187,7 +206,6 @@ func TestModelAliasThinkingSuffix(t *testing.T) {
 					t.Errorf("Case #%d: thinkingBudget = %d, want %d", tt.id, int(budgetVal.Int()), expectedBudget)
 				}
 			}
-			}
 		})
 	}
 }